WASHINGTON – It's been nearly 50 years since a General Motors executive made a public apology before Congress, acknowledging that the giant car maker had hired private detectives to harass a young, crusading lawyer for auto safety by the name of Ralph Nader.

The March 1966 hearing was as riveting in its time as GM chief Mary Barra's apology for faulty ignition switches was Tuesday on Capitol Hill.

Barra, who just took over the helm of the GM in January, went before the House Energy and Commerce Committee's panel on Oversight and Investigations to acknowledge GM's failure to recall the switches, which have been linked to 13 deaths.

“Today's GM will do the right thing,” she said. “That begins with my sincere apologies to everyone who has been affected by this recall – especially to the families and friends of those who lost their lives or were injured. I am deeply sorry.”

To Clarence Ditlow, executive director of the Nader-founded Center for Auto Safety, Barra's contrition was a defining moment. “This is the first public apology by a top GM executive since 1966,” he said. “That's the significance.”

Ditlow said that while the car industry has been responsible other safety flaws since then, “GM does not apologize easily.” In 1966, GM President James Roche apologized at a Senate subcommittee hearing for the “kind of harassment to which Mr. Nader has apparently been subjected.” The year before, Nader had published his groundbreaking investigation, “Unsafe at Any Speed,” a book that exposed the American auto industry as prioritizing design and comfort over safety. Chief among his examples were design flaws in GM's popular Corvair.

GM's investigation of Nader included reportedly tapping his phones and hiring prostitutes to lure him into a compromising position. The car maker wanted to discredit him, or as Sen. Robert Kennedy, D-N.Y., who served on the Senate committee, said then, “possibly blackmail” him. Nader sued GM and settled for $425,000, a record at the time. He used the money to fund his consumer activist organizations, staffed by what came to be known as “Nader's Raiders.”